In a chromatograph device such as a liquid chromatograph device and a gas chromatograph device, a plurality of components contained in a sample are temporally separated in a column and sequentially detected by a detector such as a mass spectrometer and an absorbance detector. A chromatograph device using a mass spectrometer as a detector is called a chromatograph mass spectrometry device. In a chromatograph mass spectrometry device, components separated in a column and eluted along with a mobile phase are sequentially ionized and mass-separated, and only ions derived from components in the sample are detected.
The mass separation is broadly divided into two modes, one being a selected ion monitoring (SIM) mode in which only ions with a specific mass-to-charge ratio are allowed to pass through a mass separation section and the other being a scan mode in which the mass-to-charge ratio of ions allowed to pass through the mass separation section is scanned. In the SIM mode, ions having a specific mass-to-charge ratio can be measured for a longtime, and thus the sensitivity and precision of the ion detection are high. The scan mode, in the meantime, is characterized in that ions with a mass-to-charge ratio within a scanning range can be exhaustively measured. Accordingly, the SIM mode is used for component measurement when the mass-to-charge ratio of generated ions is known, and the scan mode is used otherwise.
The chromatograph mass spectrometry device is used for quantification of a plurality of known components (hereinafter, referred to as “target components”) such as measurement of pesticide residues contained in foods such as agricultural crops. The SIM mode is used in this measurement as described above, and thus the measurement conditions thereof include a mass-to-charge ratio for detecting each target component. In general, ions generated from different components have different mass-to-charge ratios, and thus different mass-to-charge ratios are normally associated with the plurality of target components. In this manner, mass-to-charge ratios are used as measurement parameters in the chromatograph mass spectrometry device.
After mass-to-charge ratios are associated for every target component, a sample is introduced into the chromatograph mass spectrometry device, and (ions generated from) the target component is measured with the mass-to-charge ratio (measurement parameter) switched before the timing at which each target component begins to elute from the column. The timing (switching time) at which the measurement parameter is switched can be determined by, for example, using the intermediate timing between the retention times of two target components eluted in succession from the column (times corresponding to peak tops of a chromatogram) as the switching time for the measurement parameters of the two components on the basis of the retention time of each target component acquired by, for example, (ions generated from) a standard sample being measured under a condition in which the column type, the mobile phase type, and the mobile phase flow velocity are the same as during actual sample measurement.
Likewise, in a chromatograph device provided with an absorptiometer as a detector, a specific wavelength is associated with each target component as a measurement parameter and the wavelength (measurement parameter) is switched between the retention times for two target components eluted in succession (for example, Patent Document 1).
Patent Document 1: JP-A-61-128165